Landmark Study Demonstrates Climate Benefits of Estuary Restoration

WASHINGTON – Restore America’s Estuaries has released the findings of a groundbreaking study that confirms the climate mitigation benefits of restoring tidal wetland habitat in the Snohomish Estuary, located within the nation’s second largest estuary: Puget Sound. The study, the first of its kind, finds major climate mitigation benefits from wetland restoration and provides a much needed approach for assessing carbon fluxes for historic drained and future restored wetlands which can now be transferred and applied to other geographies.

The Study, “Coastal Blue Carbon Opportunity Assessment for Snohomish Estuary: The Climate Benefits of Estuary Restoration” finds that currently planned and in-construction restoration projects in the Snohomish estuary will result in at least 2.55 million tons of CO2 sequestered from the atmosphere over the next 100-years. This is equivalent to the 1-year emissions for 500,000 average passenger cars. If plans expanded to fully restore the Snohomish estuary, the sequestration potential jumps to 8.8 million tons of CO2 or, in other terms, equal to the 1-year emissions of about 1.7 million passenger cars.

“The study is the first to provide a science-based assessment of climate benefits from restoration at scale. The findings are clear: restoring coastal wetlands must be recognized for their ability to mitigate climate change,” said Jeff Benoit, President and CEO of Restore America’s Estuaries. “The report adds to our list of science-based reasons why restoration is so critical.”

“Healthy estuaries mean healthy economies,” Representative Rick Larsen, WA-02, said. “I have long advocated to restore our estuaries because of the critical role they play in supporting recovery of fisheries. This new study shows that estuary restoration can play a big role in countering climate change too.”

“It is very fitting that we are implementing some of the world’s leading Blue Carbon research here in Puget Sound,” said Steve Dubiel, Executive Director of EarthCorps. “We have always known that wetlands are a kind of breadbasket, thanks to the salmon and shellfish they support. Now we are learning that they are also a carbon sponge.”

In addition to the climate benefits outlined by the study, healthy and restored estuaries act as spawning grounds and nurseries for commercially and recreationally important fish and shellfish species, provide storm buffers for coastal communities, filter pollutants, and provide habitat for numerous species of fish and wildlife, as well as recreational opportunities for hundreds of millions of Americans annually.

“This study illustrates the contribution of tidal wetland restoration to reduce global warming,” said Dr. Steve Crooks, Climate Change Program Manager for Environmental Science Associates and lead author on the study. “From this analysis we find wetlands restoration in Puget Sound likely to be highly resilient to sea level rise while at the same time continuing to sequester carbon within organic soils. Similar opportunities will exist in other coastal regions of the U.S.”

“This report is a call to action. We need to invest more substantially in coastal restoration nationwide and in science to increase our understanding of the climate benefits which accrue from coastal restoration and protection efforts,” said Emmett-Mattox, Senior Director for Restore America’s Estuaries and co-author on the study. “Sea-level rise will only make restoration more difficult and costly in the future. The time for progress is now.”

This report was a collaborative effort of Restore America’s Estuaries, Environmental Science Associates (ESA), EarthCorps, and Western Washington University. Lead funding was provided by NOAA’s Office of Habitat Conservation and additional support was provided by The Boeing Company and the Wildlife Forever Fund.

“Coastal Blue Carbon Opportunity Assessment for Snohomish Estuary: The Climate Benefits of Estuary Restoration” full report is available here, and the Executive Summary is available here.